Epoxy Resin Particles, 3. Particle Formation of Epoxy Resin in Aqueous Emulsion State

A Bisphenol A‐type epoxy resin is readily emulsified in aqueous medium with an ethylene oxide adduct to a Friedel‐Crafts reaction product of styrene and 4‐(4‐cumyl)phenol as emulsifier. The resultant epoxy resin emulsion is reacted with amine‐type hardeners to obtain epoxy resin particles that are fully cross‐linked. The size and size distribution of the resultant particles are almost comparable to those of the primarily formed emulsion particles which are determined by the amount of emulsifier, mixing temperature and speed. The average diameter of the finally obtained particles ranges from 0.5 to 22 μm depending on the reaction conditions. The particles hardened with 1,2‐diaminoethane (DEA) have a spherical form with homogeneous surface, whereas the particles hardened with N,N ′‐bis(2‐aminoethyl)‐1,2‐diaminoethane (TTA) have a shrunk appearance with rough surface. These particles can readily be isolated from the dispersion without causing the solvent‐derived pollution for environment.